Не хочет принимать миграцию.

maigraciya.rb

class CreateTaskstatuses < ActiveRecord::Migration
  def change
    create_table :taskstatuses do |t|
      t.reference :user
      t.reference :task
      t.string :task_status

      t.timestamps null: false
    end

    add_foreign_key :taskstatuses, :tasks
    add_foreign_key :taskstatuses, :users

    add_index :taskstatuses, [:task_id, :user_id], :unique => true
  end
end